1. Field of the Invention
The present invention to aqueous, structured compositions (i.e., duotropic liquids) containing secondary alcohol sulfate (SALS). More particularly, aqueous, structured compositions comprising defined levels of SALS having a specified isomeric distribution yield enhanced performance and stability benefits relative to amounts and types of secondary alcohol sulfates falling outside the scope of the invention.
2. Related Art
The use of alcohol sulfates generally in aqueous structured compositions is known, for example, from U.S. Pat. No. 5,147,576 to Montague et al. While this reference does not exclude the use of secondary alcohol sulfates, nor does it specifically identify the compounds, let alone their use in critical amounts and in critical isomer distribution (i.e., minimal levels of total secondary alcohol sulfate must be 2 or 3 isomer).
WO 91/16409 to Donker also discloses the use of primary alcohol sulfates in structured liquids (i.e., duotropic liquids). Secondary alcohol sulfates are not disclosed. In addition, the application specifies that at least 20% of the primary alcohol sulfate should be branched.
U.S. Pat. No. 4,235,752 to Rossall discloses hand dishwashing liquids containing up to 50% 2,3 isomer of secondary alcohol sulfate. This reference relates to use of secondary alcohol sulfate in an isotropic (i.e., non-structured) composition. As such, the benefits of the secondary alcohol sulfate of the invention in duotropic, structured liquids could not possibly be appreciated and there would have been no motivation to use these sulfates in the structured liquids.